Operative Obstetrics (Instrumental Vaginal Delivery) PDF

DR-Mohammed Salah Operative obstetrics Operative obstetrics refers to any method used to deliver the fetus other than uterine contractions and maternal pushing efforts. It may include vaginal (Instrumental delivery) or cesarean routes.  Operative Vaginal Birth  Operative birth de...

DR-Mohammed Salah Operative obstetrics Operative obstetrics refers to any method used to deliver the fetus other than uterine contractions and maternal pushing efforts. It may include vaginal (Instrumental delivery) or cesarean routes.  Operative Vaginal Birth  Operative birth delivery is an important component of modern obstetrics.  Its purpose is to achieve or expedite a vaginal delivery.  The rate of operative deliveries has significantly decreased in the last two decades, accounting for part of the increase in cesarean delivery rates. Benefits:  Avoids cesarean birth and its associated complications  Hemorrhage | Infection | Prolonged healing time | Increased cost | Likelihood of repeat cesarean birth and associated placental abnormalities in subsequent pregnancies.  Can be accomplished quicker than cesarean birth Types of Instruments:  Vacuum: believed to be easier to learn and may be used with asynclitism.  Forceps: more secure application and appropriate for rotation ❖Mid forceps ❖Low forceps ❖Outlet forceps  FORCEPS Obstetric forceps are metal instruments used to provide traction, rotation, or both to the fetal head. Classification for use is as follows:  Outlet (most common forceps use): Fig 3 - Measuring the station of the fetus, in relation to the ischial spines. fetal head is on pelvic floor.  Low: fetal head is below +2 station but has not reached the pelvic floor.  Mid (seldom used today): fetal head is below 0 station but has not reached +2 station.  High (never appropriate in modern obstetrics because of risk to both mother and fetus): fetal head is unengaged, above 0 station. Indications are as follows:  Prolonged second stage (most common indication for forceps): may be because of dysfunctional labor or suboptimal fetal head orientation.  Category III EFM strip: fetal heart rate monitor pattern suggests fetus is not tolerating labor.  Avoid maternal pushing: include various conditions in which pushing efforts may be hazardous to parturient, e.g., cardiac, pulmonary, or neurologic disorders.  Breech presentation: shorten the time to deliver the head of a vaginal breech fetus. Prerequisites include the following:  Cervix fully dilated and retracted  Membranes ruptured  Engagement of the fetal head  Position of the fetal head has been determined  Fetal weight estimation performed  Pelvis thought to be adequate for vaginal birth  Adequate anesthesia  Maternal bladder has been emptied  Patient has agreed after being informed of the risks and benefits of the procedure  Willingness to abandon trial of operative vaginal birth and back-up plan in place in case of failure to delivery Contraindications:  Fetal head unengaged.  Position of the head is unknown.  Known or strongly suspected fetal bone demineralization condition or bleeding disorder.  Lack of experienced provider. Complications: Fetal Maternal 1) Neonatal jaundice 1) Vaginal tears 2) Scalp lacerations 2) 3rd/4th degree perineal tears: 3) Cephalhaematoma 3) VTE 4) Subgaleal hematoma 4) Incontinence 5) Facial bruising 5) PPH 6) Facial nerve damage 6) Shoulder dystocia 7) Skull fractures 7) Infection 8) Retinal hemorrhage Further Considerations: Estimated Fetal Weight Judicious use of operative vaginal delivery with suspected macrosomia Consider adequacy of pelvis, progress of labor during second stage Episiotomy Episiotomy should not be routinely performed with operative vaginal delivery Prophylactic Antibiotics Routine prophylactic antibiotics before operative vaginal delivery are not suggested Trial of Operative Vaginal Delivery Should be performed by experienced provider and have cesarean services readily available  VACUUM EXTRACTOR A vacuum extractor is a cuplike instrument that is held against the fetal head with suction. Traction is thus applied to the fetal scalp, which along with maternal pushing efforts results in descent of the head leading to vaginal delivery. The cups may be metal or plastic, rigid or soft. To use the ventouse, the cup is applied with its centre over the flexion point on the fetal skull (in the midline, 3cm anterior to the posterior fontanelle). During uterine contractions, traction is applied perpendicular to the cup. Ventouse deliveries are associated with: Lower success rate Less maternal perineal injuries Less pain More cephalhaematoma More subgaleal hematoma More fetal retinal haemorrhage  A vacuum extractor has some advantages over forceps:  Fetal head orientation: Precise knowledge of fetal head position and attitude is not essential.  Space required: The vacuum extractor does not occupy space adjacent to the fetal head.  Perineal trauma: Third- and fourth-degree lacerations are fewer.  Head rotation: Fetal head rotation occurs spontaneously at the station best suited to fetal head configuration and maternal pelvis. A vacuum extractor has some disadvantages over forceps:  Cup pop-offs: Excessive traction can lead to sudden decompression as the cup suction is released.  Scalp trauma: Scalp skin injury and lacerations are common.  Subgaleal hemorrhage and intracranial bleeding are rare.  Neonatal jaundice arises from scalp bleeding.  The indications for a vacuum extractor are similar to those of forceps:  Prolonged second stage: This may be because of dysfunctional labor or suboptimal fetal head orientation.  Non-reassuring EFM strip: The FHR monitor pattern suggests the fetus is not tolerating labor.  Avoid maternal pushing: These include various conditions in which pushing efforts may be hazardous to the parturient, e.g., cardiac, pulmonary, or neurologic disorders. Prerequisites for vacuum extractor use include:  Clinically adequate pelvic dimension  Experienced operator  Full cervical dilation  Engaged fetal head  Gestational age ≥34 weeks Complications: Complications can include vaginal lacerations from entrapment of vaginal mucosa between the suction cup and fetal head (maternal), neonatal cephalohematoma and scalp lacerations (common), and life-threatening complications of subgaleal hematoma or intracranial hemorrhage (uncommon but associated with vacuum duration >10 min) (neonatal).  CESAREAN SECTION Cesarean section is a procedure in which the fetus is delivered through incisions in the maternal anterior abdominal and uterine walls. The overall U.S. cesarean section rate in 2011 was ~33% (includes both primary and repeat procedures).  Risks. Maternal mortality and morbidity are higher than with vaginal delivery, especially with emergency cesareans performed in labor. Maternal mortality is largely anesthetic-related, with overall mortality ratio of 25 per 100,000.  Hemorrhage: Blood loss is 2x that of a vaginal delivery, with mean of 1,000 mL.  Infection: Sites of infection include endometrium, abdominal wall wound, pelvis, urinary tract, or lungs. Prophylactic antibiotics can decrease infectious morbidity.  Visceral injury: Surrounding structures can be injured (e.g., bowel, bladder, and ureters).  Thrombosis: Deep venous thrombosis is increased in the pelvic and lower extremity veins. Uterine Incisions (1) Low segment transverse. This incision is made in the noncontractile portion of the uterus and is the one most commonly used. The bladder must be dissected off the lower uterine segment. It has a low chance of uterine rupture in subsequent labor (0.5%).  Advantages: are trial of labor in a subsequent pregnancy is safe; the risk of bleeding and adhesions is less.  Disadvantages: are the fetus(es) must be in longitudinal lie; the lower segment must be developed. (2) Classical. This incision is made in the contractile fundus of the uterus and is less commonly performed. Technically it is easy to perform, and no bladder dissection is needed. Risk of uterine rupture both before labor as well as in subsequent labor is significant (5%). Repeat cesarean should be scheduled before labor onset.  Advantages: are any fetus(es) regardless of intrauterine orientation can be delivered; lower segment varicosities or myomas can be bypassed.  Disadvantages: are trial of labor in a subsequent pregnancy is unsafe; the risk of bleeding and adhesions is higher. Indications for primary cesarean section include the following:  Cephalopelvic disproportion (CPD) (most common indication for cesarean delivery): This term literally means the pelvis is too small for the fetal head.  In actual practice, it most commonly indicates failure of the adequate progress in labor, which may be related to dysfunctional labor or suboptimal fetal head orientation.  Fetal malpresentation: This refers most commonly to breech presentation, but also means any fetal orientation other than cephalic.  Category III EFM strip: The FHR monitor pattern suggests the fetus may not be tolerating labor, but commonly this is a false-positive finding.  ELECTIVE CESAREAN Recommendations from the independent panel of experts include:  Women should be counseled individually for risks and benefits.  Women who are considering having >2 children should be aware that a cesarean section causes uterine scarring; these women should avoid a primary cesarean section.  Women should not have a cesarean section prior to 39 weeks’ gestation. Thank you